/* zutil.c -- target dependent utility functions for the compression library
 * Copyright (C) 1995-2005, 2010, 2011, 2012 Jean-loup Gailly.
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/* @(#) $Id$ */

#include "zutil.h"
#ifndef Z_SOLO
	#include "gzguts.h"
#endif

#ifndef NO_DUMMY_DECL
struct internal_state
{
	int dummy;
}; /* for buggy compilers */
#endif

const char* const z_errmsg[10] =
{
	"need dictionary",     /* Z_NEED_DICT       2  */
	"stream end",          /* Z_STREAM_END      1  */
	"",                    /* Z_OK              0  */
	"file error",          /* Z_ERRNO         (-1) */
	"stream error",        /* Z_STREAM_ERROR  (-2) */
	"data error",          /* Z_DATA_ERROR    (-3) */
	"insufficient memory", /* Z_MEM_ERROR     (-4) */
	"buffer error",        /* Z_BUF_ERROR     (-5) */
	"incompatible version",/* Z_VERSION_ERROR (-6) */
	""
};


const char* ZEXPORT zlibVersion()
{
	return ZLIB_VERSION;
}

uLong ZEXPORT zlibCompileFlags()
{
	uLong flags;

	flags = 0;
	switch( ( int )( sizeof( uInt ) ) )
	{
		case 2:
			break;
		case 4:
			flags += 1;
			break;
		case 8:
			flags += 2;
			break;
		default:
			flags += 3;
	}
	switch( ( int )( sizeof( uLong ) ) )
	{
		case 2:
			break;
		case 4:
			flags += 1 << 2;
			break;
		case 8:
			flags += 2 << 2;
			break;
		default:
			flags += 3 << 2;
	}
	switch( ( int )( sizeof( voidpf ) ) )
	{
		case 2:
			break;
		case 4:
			flags += 1 << 4;
			break;
		case 8:
			flags += 2 << 4;
			break;
		default:
			flags += 3 << 4;
	}
	switch( ( int )( sizeof( z_off_t ) ) )
	{
		case 2:
			break;
		case 4:
			flags += 1 << 6;
			break;
		case 8:
			flags += 2 << 6;
			break;
		default:
			flags += 3 << 6;
	}
#ifdef DEBUG
	flags += 1 << 8;
#endif
#if defined(ASMV) || defined(ASMINF)
	flags += 1 << 9;
#endif
#ifdef ZLIB_WINAPI
	flags += 1 << 10;
#endif
#ifdef BUILDFIXED
	flags += 1 << 12;
#endif
#ifdef DYNAMIC_CRC_TABLE
	flags += 1 << 13;
#endif
#ifdef NO_GZCOMPRESS
	flags += 1L << 16;
#endif
#ifdef NO_GZIP
	flags += 1L << 17;
#endif
#ifdef PKZIP_BUG_WORKAROUND
	flags += 1L << 20;
#endif
#ifdef FASTEST
	flags += 1L << 21;
#endif
#if defined(STDC) || defined(Z_HAVE_STDARG_H)
#  ifdef NO_vsnprintf
	flags += 1L << 25;
#    ifdef HAS_vsprintf_void
	flags += 1L << 26;
#    endif
#  else
#    ifdef HAS_vsnprintf_void
	flags += 1L << 26;
#    endif
#  endif
#else
	flags += 1L << 24;
#  ifdef NO_snprintf
	flags += 1L << 25;
#    ifdef HAS_sprintf_void
	flags += 1L << 26;
#    endif
#  else
#    ifdef HAS_snprintf_void
	flags += 1L << 26;
#    endif
#  endif
#endif
	return flags;
}

#ifdef DEBUG

#ifndef verbose
	#define verbose 0
#endif
int ZLIB_INTERNAL z_verbose = verbose;

void ZLIB_INTERNAL z_error( m )
char* m;
{
	fprintf( stderr, "%s\n", m );
	exit( 1 );
}
#endif

/* exported to allow conversion of error code to string for compress() and
 * uncompress()
 */
const char* ZEXPORT zError( err )
int err;
{
	return ERR_MSG( err );
}

#if defined(_WIN32_WCE)
	/* The Microsoft C Run-Time Library for Windows CE doesn't have
	* errno.  We define it as a global variable to simplify porting.
	* Its value is always 0 and should not be used.
	*/
	int errno = 0;
#endif

#ifndef HAVE_MEMCPY

void ZLIB_INTERNAL zmemcpy( dest, source, len )
Bytef* dest;
const Bytef* source;
uInt  len;
{
	if( len == 0 )
	{
		return;
	}
	do
	{
		*dest++ = *source++; /* ??? to be unrolled */
	}
	while( --len != 0 );
}

int ZLIB_INTERNAL zmemcmp( s1, s2, len )
const Bytef* s1;
const Bytef* s2;
uInt  len;
{
	uInt j;

	for( j = 0; j < len; j++ )
	{
		if( s1[j] != s2[j] )
		{
			return 2 * ( s1[j] > s2[j] ) - 1;
		}
	}
	return 0;
}

void ZLIB_INTERNAL zmemzero( dest, len )
Bytef* dest;
uInt  len;
{
	if( len == 0 )
	{
		return;
	}
	do
	{
		*dest++ = 0;  /* ??? to be unrolled */
	}
	while( --len != 0 );
}
#endif

#ifndef Z_SOLO

#ifdef SYS16BIT

#ifdef __TURBOC__
/* Turbo C in 16-bit mode */

#  define MY_ZCALLOC

/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 * and farmalloc(64K) returns a pointer with an offset of 8, so we
 * must fix the pointer. Warning: the pointer must be put back to its
 * original form in order to free it, use zcfree().
 */

#define MAX_PTR 10
/* 10*64K = 640K */

local int next_ptr = 0;

typedef struct ptr_table_s
{
	voidpf org_ptr;
	voidpf new_ptr;
} ptr_table;

local ptr_table table[MAX_PTR];
/* This table is used to remember the original form of pointers
 * to large buffers (64K). Such pointers are normalized with a zero offset.
 * Since MSDOS is not a preemptive multitasking OS, this table is not
 * protected from concurrent access. This hack doesn't work anyway on
 * a protected system like OS/2. Use Microsoft C instead.
 */

voidpf ZLIB_INTERNAL zcalloc( voidpf opaque, unsigned items, unsigned size )
{
	voidpf buf = opaque; /* just to make some compilers happy */
	ulg bsize = ( ulg )items * size;

	/* If we allocate less than 65520 bytes, we assume that farmalloc
	 * will return a usable pointer which doesn't have to be normalized.
	 */
	if( bsize < 65520L )
	{
		buf = farmalloc( bsize );
		if( *( ush* )&buf != 0 )
		{
			return buf;
		}
	}
	else
	{
		buf = farmalloc( bsize + 16L );
	}
	if( buf == NULL || next_ptr >= MAX_PTR )
	{
		return NULL;
	}
	table[next_ptr].org_ptr = buf;

	/* Normalize the pointer to seg:0 */
	*( ( ush* )&buf + 1 ) += ( ( ush )( ( uch* )buf - 0 ) + 15 ) >> 4;
	*( ush* )&buf = 0;
	table[next_ptr++].new_ptr = buf;
	return buf;
}

void ZLIB_INTERNAL zcfree( voidpf opaque, voidpf ptr )
{
	int n;
	if( *( ush* )&ptr != 0 ) /* object < 64K */
	{
		farfree( ptr );
		return;
	}
	/* Find the original pointer */
	for( n = 0; n < next_ptr; n++ )
	{
		if( ptr != table[n].new_ptr )
		{
			continue;
		}

		farfree( table[n].org_ptr );
		while( ++n < next_ptr )
		{
			table[n - 1] = table[n];
		}
		next_ptr--;
		return;
	}
	ptr = opaque; /* just to make some compilers happy */
	Assert( 0, "zcfree: ptr not found" );
}

#endif /* __TURBOC__ */


#ifdef M_I86
/* Microsoft C in 16-bit mode */

#  define MY_ZCALLOC

#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
	#define _halloc  halloc
	#define _hfree   hfree
#endif

voidpf ZLIB_INTERNAL zcalloc( voidpf opaque, uInt items, uInt size )
{
	if( opaque )
	{
		opaque = 0;    /* to make compiler happy */
	}
	return _halloc( ( long )items, size );
}

void ZLIB_INTERNAL zcfree( voidpf opaque, voidpf ptr )
{
	if( opaque )
	{
		opaque = 0;    /* to make compiler happy */
	}
	_hfree( ptr );
}

#endif /* M_I86 */

#endif /* SYS16BIT */


#ifndef MY_ZCALLOC /* Any system without a special alloc function */

#ifndef STDC
	extern voidp  malloc OF( ( uInt size ) );
	extern voidp  calloc OF( ( uInt items, uInt size ) );
	extern void   free   OF( ( voidpf ptr ) );
#endif

voidpf ZLIB_INTERNAL zcalloc( opaque, items, size )
voidpf opaque;
unsigned items;
unsigned size;
{
	if( opaque )
	{
		items += size - size;    /* make compiler happy */
	}
	return sizeof( uInt ) > 2 ? ( voidpf )malloc( items * size ) :
		   ( voidpf )calloc( items, size );
}

void ZLIB_INTERNAL zcfree( opaque, ptr )
voidpf opaque;
voidpf ptr;
{
	free( ptr );
	if( opaque )
	{
		return;    /* make compiler happy */
	}
}

#endif /* MY_ZCALLOC */

#endif /* !Z_SOLO */
